Hello @kumarg ,
You can download the moment.js from here.
Then upload this file in the Administration > Configuration > Javascript Codes. Use the Name as cus:moment.js.
Then in your workflow you can use this to get the translated output.
loadLibrary('cus:moment.js');
moment.locale('fr');
var stringMonth=moment().format('MMMM');
logInfo(stringMonth);
The Output will be French August which is août.
Thanks